Eccentric Mass Research Articles

Bending-torsional coupling vibration characteristics of asynchronous motorized spindle considering electromechanical coupling and multi-excitation effect

For the asynchronous motorized spindle directly driven by the induction motor, the load-dependent slip ratio determines that its transient characteristics are sensitive to load. For the accurate evaluation of transient characteristics, it is necessary to deeply analyze the bending-torsional coupling vibration characteristics of the asynchronous motorized spindle with the non-ideal energy source. In this work, starting from energy conservation and clarifying the multi-physical field coupling mechanism, the bending-torsional coupling dynamic model is developed. Considering the speed fluctuation, the mass eccentricity excitation is deconstructed to explore its contribution to the coupling vibration. From the load-displacement relationship, the unbalanced excitation experienced by the journal from the bearing is modeled, considering the friction. According to the T-type equivalent circuit and mechanical characteristics of the induction motor, the electromagnetic torque considering power conservation is obtained. Furthermore, combined with Maxwell's stress formula, the electromagnetic excitation from electromagnetic torque and magnetic pull is obtained, considering the tangential and normal magnetic stress. Based on the projection and synthesis of forces, the semi-empirical mechanical cutting force model is employed to calculate the milling load. And a numerical algorithm for the fast acquisition of state-dependent delay is proposed. In particular, to reasonably characterize the energy characteristics in the system, the influence of structural vibration as an energy sink on the multi-physical field composed of mechanical, electromagnetic, and thermal fields is explored from the energy conservation. The proposed model was validated experimentally. The effects of electrical and mechanical parameters on the response are numerically discussed.

Microgravity Decoupling in Torsion Pendulum for Enhanced Micro-Newton Thrust Measurement

To enhance the accuracy of micro-Newton thrust measurements via a torsion pendulum, addressing microgravity coupling effects caused by platform tilt and pendulum mass eccentricity is crucial. This study focuses on analyzing and minimizing these effects by alleviating reference surface tilt and calibrating the center of mass during thrust measurements. The study introduced analysis techniques and compensation measures. It first examined the impact of reference tilt and center of mass eccentricity on the stiffness and compliance of the torsion pendulum by reconstructing its dynamic model. Simscape Multibody was initially employed for numerical analysis to assess the dynamic coupling effects of the tilted pendulum. The results showed the influence of reference tilt on the stiffness and compliance of the torsion pendulum through simulation. An inverted pendulum was developed to amplify the platform’s tilt angle for microgravity drag-free control. Center of mass calibration can identify the gravity coupling caused by the center of mass position. Based on the displacement signal from the capacitive sensor located at the end of the inverted pendulum, which represents the platform’s tilt angle, the pendulum’s vibration at 0.1 mHz was reduced from 5.7 μm/Hz1/2 to 0.28 μm/Hz1/2 by adjusting the voltage of piezoelectric actuator. Finally, a new two-stage torsion pendulum structure was proposed to decouple the tilt coupling buried in both pitch and roll angle. The study utilized theoretical models, numerical analysis, and experimental testing to validate the analysis methods and compensation measures for microgravity coupling effects in torsion pendulums. This led to a reduction in low-frequency noise caused by ground vibrations and thermal strains, ultimately improving the micro-Newton thrust measurement accuracy of the torsion pendulum through the platform’s drag-free control.

Seismic Response Effect on Base-Isolated Rigid Structures by Mass Eccentricity in Nuclear Plants

The purpose of this paper is to analyze the seismic response effect caused by the mass eccentricity of individual equipment when conducting base isolation for the improvement of the seismic performance of a nuclear power plant. Recent research has interpreted and confirmed through analysis and testing that base isolation for safety-related equipment in nuclear power plants is an efficient alternative to designing for excessive seismic loads. Depending on the equipment, unavoidable mass eccentricity can occur, which necessitates verification of the response impact caused by eccentricity. In this paper, we analyze the seismic response impact of equipment with mass eccentricity using small base isolators. To do so, sensitivity analysis of the seismic response due to mass eccentricity is conducted for a base-isolated concentrated mass model. Furthermore, three efficient mass eccentricity models suitable for testing are designed and manufactured. Simulation analyses using the finite element method (FEM) models are performed, followed by three-axis shake table tests to validate the seismic response impact of mass eccentricity. In conclusion, it is confirmed that applying small base isolators to equipment with mass eccentricity can affect seismic response impact to some extent when compared for a beyond-design-basis earthquake (BDBE).

Electromechanical analysis of a bending‐torsion coupling piezoelectric energy harvester

SummaryPiezoelectric energy harvester devices have been widely used for collection of the vibration energy. Especially, the cantilever structure has been extensively studied to optimizing its energy harvesting performance. In this paper, a new type of bending torsion coupled piezoelectric energy harvester is proposed with the combination of the elastic connection and the optimized design of the eccentric mass. The energy harvesting performance under indirect impact load is analyzed by the theory of mechanical vibration and Hamiltonian principle. The geometry effect of the tip mass is investigated. The theoretical calculation method is verified by comparison with the finite element method. The results show that reasonable resistance selection and the frequency matching of the main structure and the energy capture structure will significantly change the energy harvesting effect. The frequency matching of the structures can be optimized by improving the eccentric arrangement. It is demonstrated that the proposed structure of the piezoelectric energy harvester has better energy harvesting efficiency as compared with the traditional structures.

Increasing planet-stirring efficiency of debris discs by ‘projectile stirring’ and ‘resonant stirring’

ABSTRACT Extrasolar debris discs are detected by observing dust, which is thought to be released during planetesimal collisions. This implies that planetesimals are dynamically excited (‘stirred’), such that collisions are sufficiently common and violent. The most frequently considered stirring mechanisms are self-stirring by disc self-gravity, and planet-stirring via secular interactions. However, these models face problems when considering disc mass, self-gravity, and planet eccentricity, leading to the possibility that other, unexplored mechanisms instead stir debris. We hypothesize that planet-stirring could be more efficient than the traditional secular model implies, due to two additional mechanisms. First, a planet at the inner edge of a debris disc can scatter massive bodies on to eccentric, disc-crossing orbits, which then excite debris (‘projectile stirring’). Second, a planet can stir debris over a wide region via broad mean-motion resonances, both at and between nominal resonance locations (‘resonant stirring’). Both mechanisms can be effective even for low-eccentricity planets, unlike secular-planet-stirring. We run N-body simulations across a broad parameter space, to determine the viability of these new stirring mechanisms. We quantify stirring levels using a bespoke program for assessing rebound debris simulations, which we make publicly available. We find that even low-mass projectiles can stir discs, and verify this with a simple analytic criterion. We also show that resonant stirring is effective for planets above ${\sim 0.5\, {\rm M_{Jup}}}$. By proving that these mechanisms can increase planet-stirring efficiency, we demonstrate that planets could still be stirring debris discs even in cases where conventional (secular) planet-stirring is insufficient.

Vibration and stability analyses of rotor–bearing-casing system in an axial piston pump subjected to bearing faults

Healthy roller bearings are essential for the safe performance of axial piston pumps. A dynamic failure model of a rotor–bearing-casing system was developed to investigate the effect of bearing damage on the vibration characteristics and stability. This model considers the effect of large-gap circulation on a wet rotor system model, which is closely related to the stirring conditions during actual operation of axial piston pumps. The stator and rotor of the pump were modelled using the centralised parameter technique and finite element method, which were combined to develop the rotor–bearing-casing model. Vibration and stability analyses were performed for the system model with bearing failure, considering the gap annular flow and hydraulic excitation force. The effects of the mass eccentricity, rotational speed, and discharge pressure on the vibration characteristics and stability were analysed under different types of bearing failures. Furthermore, the vibration behaviour of the rotor–bearing-casing system with a bearing fault was measured to validate the established dynamic model. The results indicated that the rotational speed and rotor eccentricity affected the churning and unbalanced effects of the rotor. With an increase in the rotor eccentricity, the rotor first transitioned from nonlinear motion to one-period motion and subsequently to periodic motion. The rotor energy reduction and steady state of the rotor–bearing-casing system were induced by the rotor churning action. As the annular gap decreased, churning losses increased, resulting in a more stable rotor motion.

A genetic-continuation algorithm for bifurcation analysis of nonlinear rotordynamic systems

This study presents a combined numerical scheme with genetic algorithm and continuation method for analysing nonlinear vibrations in rotor-bearing systems. A modified genetic algorithm is developed for solving multiple coexisting roots in nonlinear rotordynamic problem. Here, the genetic objective is the completion of periodicity for the boundary values of journal/pad phase states during the consecutive generations. The arc-length continuation takes the role to extend the solutions with respect to operating parameters such as the shaft spin speed and disc mass eccentricity. The resulting bifurcation diagrams, then, can comprehensively show the emergences and disappearances of multiple response states and their stability conditions in detail, which is unlike with the commonly applied numerical integration method. A finite model of heavily loaded Jeffcott rotor supported by six-pad tilting pad journal bearing is utilized to evaluate the developed algorithm. The 150 initial states for the journal and pad are generated, and the 8 optimal results are selected and inbreeded for evolution; it repeats for 15 generations. As results, multiple coexisting responses are identified at the same condition, and various bifurcation events such as periodic doubling, saddle-node are discovered from the solution manifolds.

Influence of asymmetrical factors on aircraft ground steering stability

An aircraft taxiing on the ground is affected by several nonlinear forces so that the directional instability may occur during the steering process, and the asymmetric factors could exacerbate this phenomenon. A nonlinear asymmetrical aircraft ground taxiing dynamic model is established in MATLAB/Simulink in this study. Then the numerical continuation method based on the bifurcation theory is used to study the influence of the asymmetrical aircraft structure on the taxiing directional stability by taking the distance between the eccentric mass and the aircraft symmetry plane as the bifurcation parameter. In addition, a dual-parameter bifurcation is conducted to study the influence of the nose-wheel steering angle and the asymmetrical mass eccentric distance on the directional stability. Moreover, the effect of the asymmetrical thrust on the taxiing steering bifurcation characteristics is investigated, and the instability mechanism is revealed by analyzing the aircraft taxiing motion states under five working conditions. Then the dual-parameter bifurcation curves are obtained by introducing the nose wheel steering angle as the additional bifurcation parameter. The Bogdanov-Takens (BT) bifurcation and the Generalized Hopf (GH) bifurcation in the nonlinear ground turning dynamic system are also discussed. The results show that the asymmetrical factors can significantly affect the aircraft ground taxiing directional stability.

FRI344 Is It Possible To Have Two Endocrinopathies From Checkpoint Inhibitor Therapy At The Same Time?

Abstract Disclosure: A.N. Davis: None. G. Elshimy: None. Introduction: Checkpoint inhibitor (CPI) therapy with ipilimumab and nivolumab has become commonly used in patients with metastatic melanoma. Endocrinopathies, including hypophysitis and thyroiditis, have been reported as adverse effects. These endocrinopathies may occur with ipilimumab alone, but the incidence increases in combination therapy. Most of the cases present with one endocrinopathy at a time. We present a case highlighting the possibility of two endocrinopathies presenting simultaneously in patients treated with ipilimumab and nivolumab. Case: A 69-year-old female with stage IV choroidal melanoma presented to the ED on 7/12/22 with a sudden new onset headache for one week. CT head without contrast was unremarkable, and she was discharged home. She had been started on combination CPI therapy with ipilimumab and nivolumab on 5/26/2022, and her last dose was on 7/30/2022. An MRI brain with and without contrast was obtained by her Hematology-Oncology provider for worsening headaches on 8/15/2022 which revealed an eccentric left sellar hypo-enhancing mass that was not seen on the previous MRI brain performed on 5/24/2022. On 8/31/2022, the patient returned back to the ED with complaints of fever, weakness, altered mentation, and diarrhea. She was noted to be febrile and tachycardic with hypotension refractory to intravenous fluids. She was transferred to the medical ICU and started on a norepinephrine drip. Prior to the initiation of norepinephrine, her cortisol level was 2.40 mcg/dL with ACTH level of <5.0 pg/mL. The remainder of labs were significant for TSH <0.010 mcIU/mL, free T4 3.26 (0.58-1.76ng/dL), free T3 4.59 (2.30-4.20 pg/mL), LH 1.27 (15.9-54.0 mIU/mL), FSH 12.76 (23.0-116.3 mIU/mL), prolactin 0.56 (1.8-20.3 ng/mL), TSI <1.0 (<1.3), TRAb <1.10 (<1.75 IU/L), TPO Ab 0.5 (<9.0 IU/mL). Labs were consistent with hypopituitarism and thyrotoxicosis. She was started on stress dose hydrocortisone which was weaned to a PO maintenance dose prior to discharge. An MRI brain pituitary protocol was obtained on 9/5/2022 which revealed the same hypoattenuating sellar lesion which was slightly smaller than on the previous MRI. The patient’s presentation was attributed to pituitary apoplexy in the setting of preceding hypophysitis as well as thyroiditis. Her hypophysitis and thyroiditis were attributed to her treatment with ipilimumab and nivolumab. On 11/22/2022, free T3 was 1.83 pg/mL, free T4 was <0.25 ng/dL, and TSH was 2.538 mcIU/mL, consistent with resolved thyroiditis but developing central hypothyroidism. Discussion: CPI therapy is associated with the development of endocrinopathies including thyroiditis and hypophysitis. Our case demonstrates that it is possible for multiple endocrinopathies to present simultaneously in the setting of CPI therapy and that delay in diagnosis can precipitate adrenal crises. Given the frequency with which endocrinopathies can occur with CPI therapy, appropriate screening and follow-up are recommended in order to provide prompt diagnosis and management of these patients. Presentation: Friday, June 16, 2023

Experimental study on rotational impact dampers

Integrating the benefits of rotational nonlinear energy sinks (NESs) and impact NESs while eliminating the negative effects of impacts, rotational impact dampers (RIDs) are proposed in this study. RIDs consist of multiple eccentric masses that rotate in the same horizontal plane about a common pivot, with impacts occurring between adjacent rotators to facilitate fast and effective energy dissipation. First, the development of the RID system is presented. Subsequently, experiments are conducted on a two-story frame structure under impulse excitation to validate the feasibility of RIDs. The impacts of the RIDs with two, three, and four rotators are identified and their control effectiveness is analyzed. The experimental results demonstrate that the RIDs can effectively attenuate the vibration of the structure, with the number of rotators being the main factor affecting the control capacity. With physical validation provided, this short communication highlights the great potential of RIDs as a viable solution for control problems involving different types of uncertainties.

MASS RATIO AND ECCENTRICITY DISTRIBUTIONS OF YOUNG SPECTROSCOPIC BINARY STARS

We collected the information about 83 pre-main sequence double-lined spectroscopic binaries. Among them there are Ae/Be Herbig stars, T Tauri stars and red dwarfs. The eccentricity – period relation, the mass ratio and eccentricity distributions of young spectroscopic binaries are constructed and analyzed. The overwhelming majority of close binaries with \(P {{10}^{d}}\) have eccentricity near to zero, the stars less than 1 million years old are rare among them. The mass ratio distribution of systems with \(P {{10}^{d}}\) has a prominent maximum in a range of \(q = 0.9{\kern 1pt} - {\kern 1pt} 1.0\). The number of young spectroscopic binaries with \(P {{10}^{d}}\) does not decrease with decreasing mass ratio as sharply as in the case of close binary stars, about 12% of these stars have \(q 0.5\). The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

Distribution of Young Spectroscopic Binary Stars by Mass Ratio and Eccentricity

Distribution of Young Spectroscopic Binary Stars by Mass Ratio and Eccentricity

Dynamic field load testing of a horizontally curved longspan LRT Kuningan bridge using eccentric mass vibrator and experimental modal analysis

Light Rail Transit (LRT) infrastructure in Indonesia is developing at a rapid pace. The LRT challenging construction is the Kuningan-Longspan Curved bridge with a span of 148 meters and the radius of curvature R = 115 meter. Therefore, Kuningan LRT Bridge is considered as one of the longest concretes curved balanced cantilever LRT Bridge in the world. The implementation of bridge regulations in Indonesia requires a functional feasibility test before the bridge is operational. In the case of the Kuningan LRT bridge, functional feasibility tests were carried out in the form of static and the dynamic tests. The dynamic load test aim is finding the structure natural frequency in the vertical, Longitudinal and Transverse direction. There are 3 methods that being used to measure the dynamic parameters of the train bridge structure in Indonesia. The first method is the Impulsive method using the moving train with the speed of 25 Km/hour as a load. The second method is the usage of The Experimental Modal Analysis and the third method is the combination method of Experimental Modal Analysis with a vibrating instrument in the form of an Eccentric Mass Vibrator (Exciter). The experiment results and the modal fem from the designer is compared and presented in this paper.

Stochastic analysis of flexible rotor supported on hydrodynamic bearings

Rotating shaft instability leading to high amplitude vibration is a key problem with a wide range of industrial applications. The purpose of this study is to identify the response statistics for a conceptual model of a flexible shaft supported on hydrodynamic bearings (HDBs) and propose design strategies to reduce the response. A conceptual model of a flexible shaft with three discs supported on the HDBs is developed. A linearised model of the system is developed using the short bearing assumption. A Campbell diagram is developed for the conceptual model to identify the critical speeds wherein a high response is produced. These high responses occur at the rotor speeds corresponding to the synchronous forward whirl and the oil whip. The identified rotor speeds are validated by carrying out a run-up analysis on the test rig. Since the manufacturing process and operating conditions induce uncertainty by varying the eccentricity and the relative phase of the unbalance mass, the influence of the whirling modes on the response is investigated. The nominal positions of the unbalance masses are such that the predominant mode excited is the first mode. Experimentally a scatter plot on the maximum response at the bearing location is identified using six different positions of the eccentric mass. Further, a stochastic analysis using reduced order nonlinear model of the system is carried out. The probability density obtained is compared with a Monte Carlo simulation and the bounds of the experimental results. A control strategy is designed by altering the relative position of the unbalance masses to reduce the excitation of the first mode. The robustness of the strategy is verified by using a stochastic analysis, which indicates a reduction in the response magnitude.

ExoMMR: A New Python Package to Confirm and Characterize Mean Motion Resonances

The study of orbital resonances allows for the constraint of planetary properties of compact systems. We can predict a system’s resonances by observing the orbital periods of the planets, as planets in or near mean motion resonance (MMR) have period ratios that reduce to a ratio of small numbers. However, a period ratio near commensurability does not guarantee a resonance; we must study the system’s dynamics and resonant angles to confirm resonance. Because resonances require in-depth study to confirm, and because two-body resonances require a measurement of the eccentricity vector which is quite challenging, very few resonant pairs or chains have been confirmed. We thus remain in the era of small-number statistics, not yet able to perform large population synthesis or informatics studies. To address this problem, we build a python package to find, confirm, and analyze MMRs, primarily through N-body simulations. We then analyze all near-resonant planets in the Kepler/K2 and TESS catalogs, confirming over 60 new resonant pairs and various new resonant chains. We additionally demonstrate the package’s functionality and potential by characterizing the mass–eccentricity degeneracy of Kepler-80g, exploring the likelihood of an exterior giant planet in Kepler-80, and constraining the masses of planets in Kepler-305. We find that our methods overestimate the libration amplitudes of the resonant angles and struggle to confirm resonances in systems with more than three planets. We identify various systems that are likely resonant chains but that we are unable to confirm, and highlight next steps for exoplanetary resonances.

Quasi-periodic eruptions from mildly eccentric unstable mass transfer in galactic nuclei

ABSTRACT We propose that the recently observed quasi-periodic eruptions (QPEs) in galactic nuclei are produced by unstable mass transfer due to Roche lobe overflow of a low-mass main-sequence star in a mildly eccentric (e ∼ 0.5) orbit. We argue that the QPE emission is powered by circularization shocks, but not directly by black hole (BH) accretion. Our model predicts the presence of a time-steady accretion disc that is bolometrically brighter than the time-averaged QPE luminosity, but primarily emits in the extreme-ultraviolet. This is consistent with the quiescent soft X-ray emission detected in between the eruptions in eROSITA QPE1, QPE2, and GSN 069. Such accretion discs have an unusual νLν ∝ ν12/7 optical spectrum. The lifetime of the bright QPE phase, 102–103 yr, is set by mass-loss triggered by ram-pressure interaction between the star and the accretion disc fed by the star itself. We show that the stellar orbits needed to explain QPEs can be efficiently created by the Hills breakup of tight stellar binaries provided that (i) the stellar binary orbit is tidally hardened before the breakup due to diffusive growth of the f-mode amplitude and (ii) the captured star’s orbit decays by gravitational wave emission without significant orbital angular momentum diffusion (which is the case for low-mass BHs, MBH ≲ 106 M⊙). We conclude by discussing the implications of our model for hyper-velocity stars, extreme mass ratio inspirals, repeating partial TDEs, and related stellar phenomena in galactic nuclei.

The Effects of Near-fault Ground Motions on Optimized Triple Friction Pendulum in Asymmetric Superstructures

The effect of near-fault ground motions containing translational and rotational components is investigated by considering the analytic seismic response of a stiff single-story base-isolated asymmetric superstructure with triple friction pendulum bearing (TFPB). Firstly, six asymmetric base-isolated structures instrumented by optimum TFPBs were exposed to translational components of near-fault excitations with wide ranges of pulsive periods. Next, four single objective functions as target responses (including top floor absolute acceleration, maximum inter-story drift, base shear of structure, and isolator displacement), as well as a combined fitness function as a performance function, were determined to consider all the seismic responses simultaneously. Hence, the optimum design variables of TFPBs (including curvature radii, displacement capacity, and friction coefficient) were calculated using the Genetic Algorithm (GA) to minimize the fitness and performance functions separately for each defined eccentricity. Finally, the structural behavior in the presence of mass eccentricity on the optimum selected TFPB under transitional and transitional-rotational components was explored for a more careful comparison. Also, fifteen combinations of translational-rotational components were employed for a comprehensive investigation. The results demonstrate that roof acceleration could be increased by about 7.5% when mass eccentricity and rotational components are present at the same time.

Experimental Analysis of a Cracked Cardan Shaft System under the Influence of Viscous Hydrodynamic Forces

Accurate prediction of the dynamic behavior of coupled shafts in a fluid medium is crucial to accurately estimate equipment life and enable safe operation. However, this task is far from trivial due to the vibrations induced by the highly nonlinear nature of the machine system. This paper presents an experimental analysis of a cardan shaft under the influence of viscous hydrodynamic forces. An experimental setup was created using a cardan shaft rig installed in a plexiglas tank, with a self-aligned crack simulator supporting the driveshaft for crack extraction. Adequate instrumentation was used to measure the rotor’s fluctuation under industrial viscous fluid at various motor speeds. By analyzing the changes of unwanted high vibration, the obtained results demonstrated that the characteristics of the cracks in the fluid medium can be efficiently extracted from multiple tests using the wavelet synchrosqueezing transform and energy spectrum. This latter aspect, in particular, implies that the responses that can be observed in practice are highly sensitive to the values of the system parameters: average flow velocity, mass eccentricity, and shaft stiffness, among others. Finally, the study provides conclusions on practical applications for the reliable identification of cracks in a viscous fluid to validate the recently published theoretical study.

Performance Optimization of Ultralow-Frequency Electromagnetic Energy Harvester Driven by Eccentric mass

Driven by an eccentric mass through a two-layered cantilevered plectrum, the electromagnetic energy harvester (EEH) can convert low-frequency mechanical vibrations into continuous uni-directional rotation. To optimize the performance of the EEH, electromagnetic analysis of the EEH was conducted. Three-phase winding permanent magnet (PM) topology was employed, and combinations of different coils and magnet pole numbers were designed. Then, the finite element method (FEM) was applied to analyze the influence of the combinations of the coils and pole numbers as well as the PM dimensions on the three-phase induced voltage. Prototypes with different configurations were fabricated and the analysis effectiveness was confirmed. Furthermore, different types of stator yokes were designed to enhance the magnetic field. Compared to the original prototype, the output voltage of the optimal prototype increased by 0.5 V with the same rotation speed, and the harmonic components were sufficiently low. Then, experiments with excitation by linear reciprocating motions and swing motions were conducted. Under different exciting conditions, the optimal prototype can also induce the highest voltage amplitude. With an increase in the weight of the eccentric mass, a long duration can be reached that lasts up to 12 s. In summary, the proposed optimization can achieve a high-efficiency and high-power density EEH.

Formula omitted] fuzzy observer-based dynamic sliding mode control: Unknown input rejection approach

This article presents an H∞ fuzzy dynamic observer-based dynamic sliding mode control (SMC) for continuous-time Takagi-Sugeno (T-S) fuzzy systems in the presence of external disturbances and uncertainties. Compared with the conventional SMC and the existing approaches, the effects of the unknown input signals whether linear or nonlinear are completely eliminated. Furthermore, the nonlinear systems which are modeled as T-S fuzzy systems are allowed to share different input matrices under the proposed SMC. The matrix gains of the proposed dynamic sliding surface are derived from the solution of the linear matrix inequalities (LMIs). In addition, an H∞ fuzzy dynamic observer is proposed based on a new approach for T-S fuzzy systems affected by uncertainties and external disturbances. To reduce the analytical complexity and avoid the non-convex problem, a new transformation is used to propose both dynamic sliding surface and the dynamic observer. The stability conditions are extracted also in form of an optimization problem. Lastly, a Translational Oscillator with an eccentric Rotational proof mass Actuator (TORA) system is simulated with the proposed methods to show the superiority and effectiveness.